1. Field of the Invention
This invention relates to the chemical arts. In particular, this invention relates to lubricants, such as engine oils, hydraulic fluids, transmission fluids, cutting oils, and synthetic oils, containing boric acid.
2. Discussion of the Related Art
Lubricants serve an important function in preserving machine components and extending machine operating lifetimes. Optimization of lubricant properties has remained a primary objective as vehicle engines and other machines are operated under more demanding and difficult conditions associated with increased efficiency and performance. Numerous additives have been developed, but much remains to be done to accommodate the increased demands now being made of lubricants.
Boric acid is environmentally safe, inexpensive, and has an unusual capacity to enhance the antifriction and antiwear properties of sliding metal surfaces. Boric acid is a crystalline compound, insoluble in most petroleum-based and synthetic lubricants. Various attempts have been made to form stable lubricant compositions containing boric acid. For example, U.S. Pat. No. 5,431,830, to Erdemir, discloses lubricant compositions containing boric acid particles in a mixture and/or suspension. However, it is a drawback of such compositions that it can be difficult first to incorporate the boric acid particles in the lubricant and then to form stable products.
Accordingly, there remains a need for stable boric acid containing lubricant compositions that provide increased efficiency and performance to engines and other machines. There remains further need for stable boric acid containing lubricant compositions that can be easily prepared. The invention meets these needs and provides related advantages as well.